Electromagnetic driving module and lens device using the same

ABSTRACT

The disclosure discloses an electromagnetic driving module which includes a base, two magnetic elements, a wiring assembly, a reference element, and a sensor element. The two magnetic elements are arranged along a reference line and positioned at two sides of the base. The wiring assembly is connected to the base and arranged adjacent to the two magnetic elements. The reference element is positioned on the base. The sensor element is adjacent to the reference elements and configured to detect the movement of the reference element to position the base. A lens device using the electromagnetic driving module is also disclosed.

CROSS REFERENCE TO RELATED APPLICATIONS

This Application claims priority of Taiwan Patent Application No.102143717, filed on Nov. 29, 2013, the entirety of which is incorporatedby reference herein.

BACKGROUND OF THE DISCLOSURE Field of the Disclosure

The present Disclosure relates to a driving module and a lens deviceusing the same, and more particularly to an electromagnetic drivingmodule which converts electrical energy into mechanical energy and alens device using the same.

Description of the Related Art

Generally, an electronic device includes a driving module to drive anelement to move a predetermined distance. For example, an electronicdevice having an image capturing function usually includes a drivingmodule to generate driving power. One or more optical lens units of theelectronic device are driven by the driving power to move along anoptical axis, so as to facilitate auto-focus and auto-zoom controls.

However, since the driving module includes a complex driving member,such as step motor, ultrasonic motor, or piezoelectric actuators, etc.to generate the driving power and the driving power has to betransmitted by a number of transmission elements, it is not easy toassemble and the manufacturing cost is high. In addition, theconventional driving module is also large in size and has a high powerconsumption due to its complex construction.

Therefore, a driving module that has the advantages of small size andsimple construction is desired by the manufacturers.

BRIEF SUMMARY OF THE DISCLOSURE

Accordingly, one objective of the present disclosure is to provide anelectromagnetic driving module, which is configured to provide a drivingforce to drive an element such as a lens assembly positioned in theelectromagnetic driving module to move.

According to some embodiments of the disclosure, the electromagneticdriving module includes a base, two first magnetic elements, a wiringassembly, a reference element, and a sensor element. The two firstmagnetic elements are arranged along a first reference line and disposedon sides of the base. The wiring assembly is arranged adjacent to thetwo first magnetic elements and connected to the base. The wiringassembly is configured to allow an electric current to passtherethrough. The reference element is disposed on the base. The sensorelement is arranged adjacent to the reference element. The sensorelement is configured to detect the movement of the reference element toposition the base.

In some embodiments, the electromagnetic driving module further includestwo second magnetic elements. The two second magnetic elements arearranged along a second reference line and disposed on two sides of thebase. At least a portion of the wiring assembly faces the two secondmagnetic elements.

In some embodiments, the first reference line and the second referenceline are located on the same plane.

In some embodiments, the two first magnetic elements are point symmetricwith respect to a substantially central portion of the base, and the twosecond magnetic elements are point symmetric with respect to thesubstantially central portion of the base.

In some embodiments, the wiring assembly includes two coils. Each of thetwo coils is respectively adjacent to one of the two first magneticelements. Each of the two coils includes an upper portion and a lowerportion electrically connected to the upper portion. In addition, eachof the two first magnetic elements includes an upper magnetic poleadjacent to the upper portion and a lower magnetic pole adjacent to thelower portion. The upper magnetic pole and the lower magnetic pole havedifferent magnetic properties.

In some embodiments, the electromagnetic driving module further includesa circuit board, and the sensor element is disposed on the circuitboard. The wiring assembly is electrically connected to the circuitboard and receives an electronic signal from the outside of theelectromagnetic driving module via the circuit board.

In some embodiments, the sensor element includes a Hall effect sensor,and the reference element includes a permanent magnet.

Another objective of the present disclosure is to provide a lens device.The lens device includes any electromagnetic driving module in any ofthe embodiments mentioned above and a lens assembly disposed in theelectromagnetic driving module. The electromagnetic driving moduleadjusts the position of the lens assembly to facilitate auto-focus andauto-zoom controls.

The electromagnetic driving module of the present disclosure is drivenby a motive force provided by a magnetic element and a magnetic fieldprovided by coils as a current passes through. Therefore, an elementpositioned in the electromagnetic driving module can be moved quickly toa desired position. Compared with a conventional driving module, theelectromagnetic driving module of the present disclosure has theadvantages of low power consumption, small size, high positioningprecision, and low manufacturing cost.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the embodiments, and the advantagesthereof, reference is now made to the following descriptions taken inconjunction with the accompanying drawings.

FIG. 1 shows an exploded view of an electromagnetic driving module, inaccordance with some embodiments.

FIG. 2 shows a top view of a portion of an electromagnetic drivingmodule, in accordance with some embodiments.

FIG. 3 shows a top view of a lens device including an electromagneticdriving module, in accordance with some embodiments.

FIG. 4 shows an exploded view of an electromagnetic driving module, inaccordance with some embodiments.

FIG. 5 shows a top view of a portion of an electromagnetic drivingmodule, in accordance with some embodiments.

FIG. 6 shows an exploded view of an electromagnetic driving module, inaccordance with some embodiments.

FIG. 7 shows a top view of a portion of an electromagnetic drivingmodule, in accordance with some embodiments.

DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS

The making and using of the embodiments of the disclosure are discussedin detail below. It should be appreciated, however, that the embodimentscan be embodied in a wide variety of specific contexts. The specificembodiments discussed are merely illustrative, and do not limit thescope of the disclosure.

FIG. 1 shows an exploded view of an electromagnetic driving module 1, inaccordance with some embodiments. In one embodiment, the electromagneticdriving module 1 is a voice coil motor (VCM) which includes an upperhousing 10, an upper spring sheet 12, a frame 14, two first magneticelements 16, a base 18, a reference element 20, a wiring assembly 22, acircuit board 24, a sensor element 26, a lower spring sheet 28, and alower housing 30. The elements of the electromagnetic driving module 1can be added to or omitted, and the disclosure should not be limited bythe embodiment.

In one embodiment, the upper spring sheet 12 is fixed at the frame 14,and the lower spring sheet 28 is fixed at the lower housing 30. Theupper spring sheet 12 and the lower spring sheet 28 are configured forsupporting the base 18 and enabling the base 18 to move in a verticaldirection (X-axis). The base 18 is disposed in an accommodation space(not indicated) defined by the upper housing 10 and the lower 30. In oneembodiment, the lower spring sheet 28 includes two conductive pins 281and 283, and the two conductive pins 281 and 283 are electricallyconnected to the circuit board 24.

In one embodiment, the base 18 is penetrated by a passage 189 and isconfigured to support an assembly, such as a lens assembly (not shown inFIG. 1). In addition, the base 18 includes one or more side surfacessurrounding the passage 189. In one embodiment, the base 18 includes anumber of side surfaces, such as a first side surface 181, a second sidesurface 182, a third side surface 183, and a fourth side surface 184.The first side surface 181 is opposite to the third side surface 183,and the second side surface 182 is opposite to the fourth side surface184. The wiring assembly 22 has a circular configuration and is disposedon the first, the second, the third, and the fourth side surfaces 181,182, 183, and 184. The wiring assembly 22 is configured to allow anelectric current passing therethrough to generate a magnetic field. Inone embodiment, the wiring assembly is electrically connected to thelower spring sheet 29. The electrical current from the outside powersource is transmitted to the wiring assembly 22 via the circuit board 24and the lower spring sheet 28.

In one embodiment, the frame 14 is fixed at the upper housing 10 or thelower housing 30 and is positioned between the upper spring sheet 12 andthe lower spring sheet 28. The frame 14 includes one or more sidesub-frames. In one embodiment, the frame 14 includes four sub-frames,such as a first stab-frame 141, a second sub-frame 142, a thirdsub-frame 143, and a fourth sub-frame 144. In one embodiment, the firstsub-frame 141, a second sub-frame 142, a third sub-frame 143, and afourth sub-frame e 144 are respectively adjacent to the first sidesurface 181, a second side surface 182, a third side surface 183, and afourth side surface 184 of the base 18. A gap is formed between thesub-frames of the frame 14 and the outer surfaces of the base 18. Thereis no contact between the frame 14 and the base 18.

In one embodiment, first sub-frame 141 includes an opening 1411, and thethird sub-frame 143, which is opposite to the first sub-frame 141,includes an opening 1431. The shape of each opening 1411 and 1431corresponds to the shape of each first magnetic element 16. The twofirst magnetic elements 16 are respectively adjacent to wiring assembly22 and disposed in the openings 1411 and 1431. Additionally, the secondsub-frame 142 includes a through hole 1421 for receiving the sensorelement 26.

FIG. 2 shows a top view of the electromagnetic driving module 1, inaccordance with some embodiments. The substantially central portion ofeach first magnetic element 16 is arranged along a first reference lineR1. The first reference line R1 passes through the substantially centralportion of the base 18 and is perpendicular to the first side surface181 and the third side surface 183. Through the above-mentionedarrangements, the base 18 is stably driven to move along a verticaldirection (Z-axis) by the magnetic field generated by the two firstmagnetic elements 16 and the magnetic field generated by the wiringassembly 22. Therefore, the control accuracy of the base 18 is improved.However, it should be appreciated that the position of the two firstmagnetic elements 16 should not be limited to the embodiment. Theposition of the two first magnetic elements 16 can be modified, as alongas the base 18 can be stably driven by the magnetic force.

In one embodiment, at the vicinity of the corner 186 between the secondside surface 182 and the third side surface 183, a groove 1821 isdisposed on the second side surface 182. The reference element 20 isdisposed in the groove 1821. The sensor element 26 is arranged adjacentto the reference element 20 to position the base 18. In the embodiment,the reference element 20 is a permanent magnet, and the sensor element26 is a Hall effect sensor. By detecting the permanent magnet of thereference element 20, the sensor element 26 produces an electricalsignal based on the position of the reference element 20, so that theposition of the base 18 is measured. In another embodiment, thereference element 20 includes an optical transmitter, and the sensorelement 26 includes a position signal receiver. By receiving the signalfrom the reference element 20, the sensor element 26 produces anelectrical signal based on the position of the reference element 20, sothat the position of the base 18 is measured.

In one embodiment, the circuit board 24 is arranged adjacent to thesecond side surface 182, and the sensor element 26 is disposed on tirecircuit board 24. In the other embodiment, the sensor element 26 is notdirectly disposed on the circuit board 24, and the sensor element 26 iselectrically connected to the circuit board 24 via a conductive element.The circuit board 24 is electrically connected to an external circuitvia an opening (not shown in the figure) between the upper housing 10and the lower housing 30. In one embodiment, power or an electricalsignal from the outside is transmitted to the elements in theelectromagnetic driving module 1 via the circuit board 24, and theelectrical signal produced by the sensor element 26 is transmitted to acontrol system (not shown in the figure) via the circuit board 24. Thecontrol system adjusts the electrical current applied to the wiringassembly 24 according to the electrical signal from the sensor element26, so as to correct the position of the base 18.

FIG. 3 shows a top view of a lens device 100 including theelectromagnetic driving module 1. In one embodiment, the lens device 100includes an electromagnetic driving module 1, a lens assembly 50, and anoptical sensor 60. The lens assembly 50 is disposed on the base 18(FIG. 1) of the electromagnetic driving module 1. The light receivingside of the lens assembly 50 is adjacent to the upper housing 10, andthe light emitting side of the lens assembly 50 is adjacent to theoptical sensor 60. The optical sensor 60 is a CMOS sensor, for example.The optical sensor 60 receives light passing through the lens assembly50 and produces an image signal. The electromagnetic driving module 1controls the focal length between the lens assembly 50 and the opticalsensor 60, so as to facilitate an auto-focus and an auto-zoom control.

FIG. 4 shows an exploded view of an electromagnetic driving module 1′.In FIG. 4, elements similar to those of the electromagnetic drivingmodule 1 are provided with the same reference numbers, and the featuresthereof are not repeated in the interest of brevity. Differences betweenthe electromagnetic driving module 1′ and the electromagnetic drivingmodule 1 includes the electromagnetic driving module 1′ including aframe 32, two first magnetic elements 34, two second magnetic elements36, and a circuit board 38.

In one embodiment, the frame 32 is fixed at the upper housing 10 or thelower housing 30 and is positioned between the upper spring sheet 12 andthe lower spring sheet 28. The frame 32 includes one or more sidesub-frames. In one embodiment, the frame 32 includes four sub-frames,such as a first sub-frame 321, a second sub-frame 322, a third sub-frame323, and a fourth sub-frame 324. In one embodiment, the first sub-frame321, the second sub-frame 322, the third sub-frame 323, and the fourthsub-frame 324 are respectively adjacent to the first side surface 181,the second side surface 182, the third side surface 183, and the fourthside surface 184 of the base 18. A gap is formed between the sub-frameof the frame 32 and the outer surface of the base 18. There is nocontact between the frame 32 and the base 18.

In one embodiment, each of the first sub-frame 321, the second sub-frame322, the third sub-frame 323, and the fourth sub-frame 324 includes anopening, such as openings 3211, 3221, 3231, and 3241. The shape of eachof the openings 3211 and 3231 corresponds to the shape of each firstmagnetic element 34, and the two first magnetic elements 34 arerespectively positioned in the openings 3211 and 3231 and arrangedadjacent to the wiring assembly 22. The shape of each of the openings3221 and 3241 corresponds to the shape of each second magnetic element36, and the two second magnetic elements 36 are respectively positionedin the openings 3221 and 3241 and arranged adjacent to the wiringassembly 22. In addition, the second sub-frame 322 further includes athrough hole 3222, and the sensor element 26 is positioned in thethrough hole 3222.

FIG. 5 shows a top view of a portion of the electromagnetic drivingmodule 1′. As shown in FIG. 5, the central portion of each firstmagnetic element 34 is arranged on a first reference line R1, and thefirst reference line R1 passes through the substantially central portionof the base 18. In addition, the central portion of each second magneticelement. 36 is arranged on a second reference line R2, and the secondreference line R2 passes through the substantially central portion ofthe base 18. In one embodiment, the first reference line R1 and thesecond reference line R2 are located on the same plane. In oneembodiment, the first magnetic element 34 arranged adjacent to the firstside surface 181 and the second magnetic element 36 arranged adjacent tothe second side surface 182 are at the corner 187 between the first sidesurface 181 and the second side surface 182. In addition, the firstmagnetic element 34 arranged adjacent to the third side surface 183 andthe second magnetic element 36 arranged adjacent to the fourth sidesurface 184 are at the corner 188 between the third side surface 183 andthe fourth side surface 184. Through the above-mentioned arrangements,in the operation of the electromagnetic driving module 1″ the base 18 isable to be stably driven to move, and the control accuracy of the base18 is improved.

In one embodiment, the two first magnetic elements 34 have the samemagnetic field strength. The two second magnetic elements 36 have thesame magnetic field strength. In one embodiment, the magnetic fieldstrength of the two first magnetic elements 34 is different from themagnetic field strength of the two second magnetic elements 36. In oneembodiment, the magnetic field strength of the two first magneticelements 34 is the same as the magnetic field strength of the two secondmagnetic elements 36. Through the above-mentioned arrangements, the base18 is driven to move by the magnetic force equally applied at two sidesthereof to prevent tilting of the base 18.

In one embodiment, the circuit board 38 is arranged adjacent to thesecond side surface 182, and the second element 26 is arranged on thecircuit board 38. In one embodiment, the circuit board 38 has anL-shape, and the second magnetic elements 36 are arranged adjacent tothe circuit board 38, so as to reduce the size of the electromagneticdriving module 1′.

FIG. 6 shows an exploded view of an electromagnetic driving module 1″.In FIG. 6, elements similar to those of the electromagnetic drivingmodule 1 are provided with the same reference numbers, and the featuresthereof are not repeated in the interest of brevity. Differences betweenthe electromagnetic driving module 1″ and the electromagnetic drivingmodule 1 includes the electromagnetic driving module 1″ including a base40, a wiring assembly 41, two first magnetic elements 42, and a frame46.

In one embodiment, the base 40 is penetrated by a passage 409 and isconfigured to support an assembly, such as a lens assembly (not shown inFIG. 6). In addition, the base 40 includes one or more side surfacessurrounding the passage 409. In one embodiment the base 40 includes anumber of side surfaces, such as a first side surface 401, a second sidesurface 402, a third side surface 403, and a fourth side surface 404.The first side surface 401 is opposite to the third side surface 403,and the second side surface 402 is opposite to the fourth side surface404. In addition, as shown in FIG. 6, the base 40 includes a number ofpositioning elements 4032 formed at the first side surface 401 and thethird side surface 403 for fixing the wiring assembly 41.

The wiring assembly 41 includes two coils 42. The two coils 42 arerespectively fixed on the first side surface 401 and the third sidesurface 403 of the base 40. Each of the two coils 42 includes an upperportion 421 and a lower portion 423 electrically connected to the upperportion 421. In one embodiment, the two coils 42 are electricallyconnected to the circuit board 24 via the lower spring sheet 28. When anelectrical current from the outside is applied to each coil 42, the flowdirection of the electrical current in the upper portion 421 is oppositeto the flow direction of the electrical current in the lower portion423. That is, the direction of the magnetic field generated by the upperportion 421 is opposite to the direction of the magnetic field generatedby the lower portion 423.

In one embodiment, the frame 46 is fixed at the upper housing 10 or thelower housing 30 and is positioned between the upper spring sheet 12 andthe lower spring sheet 28. The frame 46 includes one or more sidesub-frames. In one embodiment, the frame 46 includes four sub-frames,such as a first sub-frame 461, a second sub-frame 462, a third sub-frame463, and a fourth sub-frame 464. In one embodiment, the first sub-frame461, the second sub-frame 462, the third sub-frame 463, and the fourthsub-frame 464 are respectively adjacent to the first side surface 401,the second side surface 402, the third side surface 403, and the fourthside surface 404 of the base 40. A gap is formed between the sub-frameof the frame 46 and the outer surface of the base 40. There is nocontact between the frame 46 and the base 40.

In one embodiment, the first sub-frame 461 includes an opening 4611, andthe third sub-frame 463 which is opposite to the first sub-frame 461includes an opening 4631. The shape of each of the openings 4611 and4631 corresponds to the shape of each first magnetic element 48. The twofirst magnetic elements 48 are arranged adjacent to wiring assembly 22and respectively positioned in the openings 4611 and 4631. In addition,the second sub-frame 462 further includes a through hole 4621, and thesensor element 26 is disposed in the through hole 4621.

In one embodiment, each of the two first magnetic elements 48 includesan upper magnetic pole 481 and a lower magnetic pole 483. The uppermagnetic pole 481 is adjacent to the upper portion 421, and the lowermagnetic pole 483 is adjacent to the lower portion 423. At one side ofeach of the two first magnetic elements 48 that faces to the coil 42,the upper magnetic pole 481 and the lower magnetic pole 483 havedifferent magnetic properties. For example, at one side of the firstmagnetic element 48 that faces the coil 42, the upper magnetic pole 481has a north magnetic polarity, and the lower magnetic pole 483 has asouth magnetic polarity. In one embodiment, since the circular wiringassembly 22 (FIG. 1) is replaced by the two coils 42, the size of theelectromagnetic driving module 1″ reduced.

FIG. 7 shows a top view of part of the electromagnetic driving module1″. As shown in FIG. 7, the substantial central portion of each firstmagnetic element 16 is arranged along a first reference line R1. Thefirst reference line R1 passes through the substantial central portionof the base 40, but the first reference line R1 is not perpendicular tothe first side surface 401 and the third side surface 403. That is, oneof the first magnetic elements 48 is adjacent to a corner 405 betweenthe first side surface 401 and the fourth side surface 404, and theother first magnetic element 48 is adjacent to a corner 405 between thesecond side surface 402 and the third side surface 403. Through theabove-mentioned arrangements, in the operation of the electromagneticdriving module 1″, the base 40 is able to be stably driven to move, andthe control accuracy of the base 40 is improved. However, the positionof the two first magnetic elements 48 should not be limited to theembodiment. The position of the two first magnetic elements 48 can bemodified as long as the base 40 can be stably driven to move.

In one embodiment, at a corner 407 between the first side surface 401and the second side surface 402 of the base 40, an accommodation groove4021 is formed on the second side surface 402 of the base 40. Thereference element 20 corresponds to the sensor element 26 and ispositioned in the accommodation groove 4021.

In the present disclosure, with the sensor element, the position of thebase of the electromagnetic driving module can be instantly analyzed bya control system. Therefore, the control precision is improved. Inaddition, since the electromagnetic driving module is connected to anoutside circuit via the circuit board, the processing time forassembling the electromagnetic driving module and the other element(such as a motherboard) is decreased. Therefore, production efficiencyis improved and the manufacturing cost is reduced.

While the disclosure has been described by way of example and in termsof preferred embodiment, it is to be understood that the disclosure isnot limited thereto. On the contrary, it is intended to cover variousmodifications and similar arrangements (as would be apparent to thoseskilled in the art). Therefore, the scope of the appended claims shouldbe accorded the broadest interpretation so as to encompass all suchmodifications and similar arrangements.

What is claimed is:
 1. An electromagnetic driving module, comprising: abase, having a groove; two first magnetic elements, arranged along afirst reference line and disposed on two sides of the base; a wiringassembly, situated on a reference plane with the first reference lineextended thereon, arranged adjacent to the two first magnetic elementsand connected to the base, wherein the wiring assembly is configured toallow an electric current to pass therethrough; a reference element,disposed in the groove of the base; and a sensor element, arrangedadjacent to the reference element and configured to detect the movementof the reference element to position the base; wherein the sensorelement is disposed to face the reference element in a directionparallel to the reference plane, and the wring assembly is positionedbetween the reference element and the sensor element along the directionparallel to the reference plane.
 2. The electromagnetic driving moduleas claimed in claim 1, further comprising two second magnetic elementsarranged along a second reference line and disposed on two sides of thebase, wherein at least a portion of the wiring assembly faces the twosecond magnetic elements.
 3. The electromagnetic driving module asclaimed in claim 2, wherein the first reference line and the secondreference line are located on the same plane.
 4. The electromagneticdriving module as claimed in claim 2, wherein the two first magneticelements are point symmetric with respect to a substantially centralportion of the base, and the two second magnetic elements are pointsymmetric with respect to the substantially central portion of the base.5. The electromagnetic driving module as claimed in claim 1, wherein thewiring assembly comprises two coils, the two coils are respectivelyadjacent to one of the two first magnetic elements, and each of the twocoils comprises an upper portion and a lower portion electricallyconnected to the upper portion; and wherein each of the two firstmagnetic elements comprises an upper magnetic pole adjacent to the upperportion and a lower magnetic pole adjacent to the lower portion, and theupper magnetic pole and the lower magnetic pole have different magneticproperties.
 6. The electromagnetic driving module as claimed in claim 1,further comprising a circuit board, and the sensor element is disposedon the circuit board.
 7. The electromagnetic driving module as claimedin claim 6, wherein the wiring assembly is electrically connected to thecircuit board and receives an electronic signal from the outside via thecircuit board.
 8. The electromagnetic driving module as claimed in claim1, wherein the sensor element comprises a Hall effect sensor, and thereference element comprises a permanent magnet.
 9. A lens device,comprising an electromagnetic driving module as claimed in claim 1, anda lens assembly disposed in the electromagnetic driving module.
 10. Thelens device as claimed in claim 9, further comprising an optical sensorarranged adjacent to the lens assembly.